The present invention relates to an anti-fouling, semi-permeable membrane comprising a porous support layer, a thin film composite (TFC) layer formed on a surface of the support layer, and a cross-linked polyvinyl alcohol (PVA) layer formed on top of the TFC layer, wherein the cross-linked PVA layer is the reaction product of PVA and a cross-linking agent, said cross-linking agent being a polybasic acid comprising three or more acid groups or precursors thereof. The obtained membrane shows a high water flux and a low roughness suitable for an effective membrane notable for feed solution having a tendency of fouling the membrane.

The present invention provides a composition for a CO.sub.2 gas separation membrane containing: at least one compound selected from the group consisting of an alkali metal carbonate, an alkali metal bicarbonate, and an alkali metal hydroxide; a crosslinked polymer in which a polymer having a carboxyl group has been crosslinked; and a non-crosslinked polymer obtained by polymerization of one or more monomers selected from the group consisting of vinyl acetate, acrylic acid, methacrylic acid, and a derivative thereof.

The present invention provides a composition for a CO.sub.2 gas separation membrane containing: at least one compound selected from the group consisting of an alkali metal carbonate, an alkali metal bicarbonate, and an alkali metal hydroxide; a crosslinked polymer in which a polymer having a carboxyl group has been crosslinked; and a non-crosslinked polymer obtained by polymerization of one or more monomers selected from the group consisting of vinyl acetate, acrylic acid, methacrylic acid, and a derivative thereof.

Provided is a method for separating, from a raw gas containing a specific gas, the specific gas using a gas separation membrane module. The gas separation membrane module includes a housing and a gas separation membrane element enclosed in the housing. The gas separation membrane element includes a gas separation membrane including a hydrophilic resin composition layer for selectively allowing for permeation of the specific gas. The method includes the steps of: increasing pressure in an interior of the gas separation membrane module; increasing a temperature in the interior of the gas separation membrane module; and feeding a raw gas to the interior of the gas separation membrane module in that order.

A copolymer is excellent in water permeability, suppression of platelet adhesion, and suppression of protein adhesion, and a separation membrane, a medical device, and a separation membrane module for medical use using the copolymer. The copolymer includes monomer units derived from two or more types of monomers, wherein the hydration energy density of the copolymer is 158.992 to 209.200 kJ.Math.mol.sup.1.Math.nm.sup.3, the monomer unit with the highest hydration energy density in the monomer units is a monomer unit not containing a hydroxy group, the volume fraction of the monomer unit with the highest hydration energy density in the monomer units is 35 to 90%, and the difference in hydration energy density is 71.128 to 418.400 kJ.Math.mol.sup.1.Math.nm.sup.3.

Hollow fiber membranes having improved toughness and durability are prepared using a vinylidene fluoride polymer-containing component, such as Kynaro resins, having relatively low crystallinity. One aspect of the invention provides a membrane in the form of a fiber, wherein i) the fiber has a porous wall of a polymeric component enclosing a central hollow space extending the length of the fiber, ii) the polymeric component has a crystallinity as determined by wide angle x-ray diffraction of less than about 35%, iii) the polymeric component is comprised of at least one homopolymer or copolymer of vinylidene fluoride and iv) the membrane has an energy to break of at least about 0.5 J per square mm of membrane cross section.

Membranes of the present disclosure possess very thin barrier layers, with high selectivity, high throughput, low fouling, and are long lasting. The membranes include graphene and/or graphene oxide barrier layers on a nanofibrous supporting scaffold. Methods for forming these membranes, as well as uses thereof, are also provided. In embodiments, an article of the present disclosure includes a nanofibrous scaffold; at least a first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof on at least a portion of a surface of the nanofibrous scaffold; an additive such as crosslinking agents and/or particles on an outer surface of the at least first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof.

Provided is a method for separating, from a raw gas containing a specific gas, the specific gas using a gas separation membrane module. The gas separation membrane module includes a housing and a gas separation membrane element enclosed in the housing. The gas separation membrane element includes a gas separation membrane including a hydrophilic resin composition layer for selectively allowing for permeation of the specific gas. The method includes the steps of: increasing pressure in an interior of the gas separation membrane module; increasing a temperature in the interior of the gas separation membrane module; and feeding a raw gas to the interior of the gas separation membrane module in that order.

Membranes of the present disclosure possess very thin barrier layers, with high selectivity, high throughput, low fouling, and are long lasting. The membranes include graphene and/or graphene oxide barrier layers on a nanofibrous supporting scaffold. Methods for forming these membranes, as well as uses thereof, are also provided. In embodiments, an article of the present disclosure includes a nanofibrous scaffold; at least a first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof on at least a portion of a surface of the nanofibrous scaffold; an additive such as crosslinking agents and/or particles on an outer surface of the at least first layer of nanoporous graphene, nanoporous graphene oxide, or combinations thereof.

The present invention aims to provide a gas-selective permeable membrane that has gas permeability and gas selectivity capable of highly separating a target gas from other gases, is less likely to be influenced by the temperature condition employed, and is excellent in strength and handleability. The invention uses at least one or more polymerizable compounds to provide a gas-selective permeable film that contains a polymer having an optically uniaxial or multiaxial molecular alignment and to provide a laminate including a gas-permeable substrate and the permeable membrane laminated thereon.